Let them eat during dialysis: an overlooked opportunity to improve outcomes in maintenance hemodialysis patients

Hemodialysis Procedures for Stable Incident and Prevalent Patients Optimize Hemodynamic Stability, Dialysis Dose, Electrolytes, and Fluid Balance

The demographic profile of patients transitioning from chronic kidney disease to kidney replacement therapy is changing, with a higher prevalence of aging patients with multiple comorbidities such as diabetes mellitus and heart failure. Cardiovascular disease remains the leading cause of mortality in this population, exacerbated by the cardiovascular stress imposed by the HD procedure. The first year after transitioning to hemodialysis is associated with increased risks of hospitalization and mortality, particularly within the first 90-120 days, with greater vulnerability observed among the elderly. Based on data from clinics in Fresenius Medical Care Europe, Middle East, and Africa NephroCare, this review aims to optimize hemodialysis procedures to reduce mortality risk in stable incident and prevalent patients. It addresses critical aspects such as treatment duration, frequency, choice of dialysis membrane, dialysate composition, blood and dialysate flow rates, electrolyte composition, temperature control, target weight management, dialysis adequacy, and additional protocols, with a focus on mitigating prevalent intradialytic complications, particularly intradialytic hypotension prevention.

Quality characteristics and sensory evaluation of protein-rich baked snacks for adults with chronic kidney disease: a proof of concept study

BACKGROUND

Adults with chronic kidney disease (CKD) have different protein requirements than the general population. Limited protein-rich baked snack options are available for CKD adults. The purpose of this proof of concept study was to develop two protein-rich baked snacks made with whey protein isolate and soy protein isolate and to evaluate their quality characteristics and sensory perceptions for adults with CKD.

METHODS

A control formulation was obtained from the American Association of Cereal Chemists to develop three formulations-dried milk (control), whey protein isolate and soy protein isolate at an unbaked weight of 30 g. Product quality characteristics included moisture content, water activity, shape and size, and texture profile. For the sensory perception, healthy adults (n = 101) and adults with CKD (n = 57) completed a 9-point hedonic scale for appearance, flavor, texture, and overall acceptability.

RESULTS

Protein content for the whey protein isolate and soy protein isolate reached 20% total weight. Despite containing similar moisture, both formulations were harder than the control (p < 0.001). Healthy participants preferred the whey protein isolate-based snack over the soy protein isolate-based snack for all attributes (p < 0.05). Differences in the same attributes were not perceived among CKD participants (p > 0.05). Open-ended responses from both healthy and CKD participants indicated that the soy protein isolate formulation was softer and sweeter compared to the whey protein isolate formulation.

CONCLUSION

Overall, adults with CKD preferred both the whey protein isolate-and soy protein isolate-formulated snacks. These protein-rich baked snacks can be further modified to serve as an alternative snack choice for adults with CKD and used in future clinical trials.

Paraoxonase 1 Activity and Renal Replacement Therapy for Chronic Renal Failure: A Meta-Analysis

Chronic renal failure (CRF) is associated with the development of cardiovascular disease (CVD). Paraoxonase 1 (PON1), an antioxidant enzyme, shows cardioprotective properties and has been proposed as a therapeutic marker for CRF. A systematic analysis of the literature assessing the association between PON1 activity and renal replacement therapy (RRT) of CRF is currently lacking. Therefore, we set out to perform a meta-analysis of the available data on PON1 in RRT of CRF. We searched three electronic databases for studies on PON1 activity in CRF patients with RRT such as hemodialysis (HD), peritoneal dialysis (PD), or renal transplantation (RTx), published before June 2023. A random-effects and network meta-analysis were performed. A total of 53 studies were eligibly identified. Compared to CRF patients without RRT, RTx patients had higher paraoxonase activity (standard mean difference (SMD), 1.76, 95% confidence interval (CI), 0.76-2.75), followed by HD (SMD, 0.73; 95% CI, 0.02-1.45) and PD patients. Likewise, RTx patients had higher arylesterase activity (SMD, 1.84, 95% CI, 0.18-3.50), followed by HD and PD patients. Also, paraoxonase activity was increased after HD (SMD, 0.59, 95% CI, 0.16-1.03). In conclusion, the overall data demonstrated that PON1 activity is higher in CRF patients with RRT, particularly RTx, followed by that of HD and PD. Measuring PON1 activity can also be included to the paraclinical toolbox for the management of RRT, in addition to the understanding of CRF-related pathophysiology. Regarding the selection of RRT types and their potential to prevent CVD, more research is required.

Intradialytic Protein Ingestion and Exercise do Not Compromise Uremic Toxin Removal Throughout Hemodialysis

OBJECTIVE

Dietary protein and physical activity interventions are increasingly implemented during hemodialysis to support muscle maintenance in patients with end-stage renal disease (ESRD). Although muscle maintenance is important, adequate removal of uremic toxins throughout hemodialysis is the primary concern for patients. It remains to be established whether intradialytic protein ingestion and/or exercise modulate uremic toxin removal during hemodialysis.

METHODS

We recruited 10 patients with ESRD (age: 65 ± 16 y, BMI: 24.2 ± 4.8 kg/m²) on chronic hemodialysis treatment to participate in this randomized cross-over trial. During hemodialysis, patients were assigned to ingest 40 g protein or a nonprotein placebo both at rest (protein [PRO] and placebo [PLA], respectively) and following 30 min of exercise (PRO + exercise [EX] and PLA + EX, respectively). Blood and spent dialysate samples were collected throughout hemodialysis to assess reduction ratios and removal of urea, creatinine, phosphate, cystatin C, and indoxyl sulfate.

RESULTS

The reduction ratios of urea and indoxyl sulfate were higher during PLA (76 ± 6% and 46 ± 9%, respectively) and PLA + EX interventions (77 ± 5% and 45 ± 10%, respectively) when compared to PRO (72 ± 4% and 40 ± 8%, respectively) and PRO + EX interventions (73 ± 4% and 43 ± 7%, respectively; protein effect: P = .001 and P = .023, respectively; exercise effect: P = .25 and P = .52, respectively). Nonetheless, protein ingestion resulted in greater urea removal (P = .046) during hemodialysis. Reduction ratios and removal of creatinine, phosphate, and cystatin C during hemodialysis did not differ following intradialytic protein ingestion or exercise (protein effect: P > .05; exercise effect: P>.05). Urea, creatinine, and phosphate removal were greater throughout the period with intradialytic exercise during PLA + EX and PRO + EX interventions when compared to the same period during PLA and PRO interventions (exercise effect: P = .034, P = .039, and P = .022, respectively).

CONCLUSION

The removal of uremic toxins is not compromised by protein feeding and/or exercise implementation during hemodialysis in patients with ESRD.

Dietary Acid Load and Predialysis Serum Bicarbonate Levels in Patients With End-Stage Renal Disease

OBJECTIVES

Maintaining the predialysis serum bicarbonate at a recommended level is critical in patients undergoing hemodialysis. Therefore, the present study investigated the association between dietary acid load (DAL) and serum predialysis bicarbonate levels in patients with end-stage renal disease.

METHODS

Adult patients undergoing hemodialysis were enrolled in this cross-sectional study. Diet was assessed using a semiquantitative food frequency questionnaire. DAL was calculated with 2 validated indices: potential renal acid load (PRAL) and net endogenous acid production (NEAP). Values regarding predialysis serum bicarbonate level and serum electrolytes were obtained from the participant's medical records. The multiple linear regression analysis was used to determine the association between DAL indices and predialysis serum bicarbonate level.

RESULTS

The number of hemodialysis patients eligible for this study was 122. The participants' mean age and body mass index was 57.14 ± 3.8 years and 25.2 ± 4.9 kg/m², respectively. About 65.6% of participants were male. The mean serum levels of predialysis bicarbonate were 21.59 ± 3.1 mEq/L. Also, 47.5% of patients had predialysis serum bicarbonate levels below the recommended value. The mean values of PRAL and NEAP were -2.8 ± 7.48 and 42.7 ± 10.1 mEq/day, respectively. PRAL significantly and inversely predicted predialysis serum bicarbonate level independent of covariates (standardized β = -0.38; P < .001). Also, NEAP was independently and inversely associated with predialysis bicarbonate level (standardized β = -0.40; P < .001). Consuming vegetables such as lettuce, tomato, cucumber, spinach, and dried fruits as well as low-fat milk, plain yogurt, and cream cheese were positively correlated to predialysis serum bicarbonate level. However, the canned tuna had a negative correlation with the predialysis serum bicarbonate.

CONCLUSIONS

The study's findings showed that the lower DAL was associated with higher predialysis serum bicarbonate levels in patients with end-stage renal disease. Due to the cross-sectional nature of the present study, prospective cohorts or well-controlled clinical trials are needed to confirm our result.

Effects of the Malnutrition-Eat Additional Meal (MEAM) Diet on the Serum Levels of Albumin and C-Reactive Protein in Hemodialysis Patients

The main objective of this project was to evaluate the efficiency of two kinds of nutritional intervention implemented in hemodialysis patients for 24 weeks (traditional nutritional intervention without a meal served before dialysis for group HG1, and nutritional intervention involving a meal served before dialysis for group HG2), and their impact on nutritional status and serum concentrations of C-reactive protein (CRP). Nutritional status and serum biochemical parameters were analyzed in the control group (CG, n = 70) and in two homogeneous groups of patients, HG1 (n = 35) and HG2 (n = 35). There was an interesting trend in both groups of patients connected with increased intake, mainly of energy and protein. In HG1, the greatest increase in energy intake was observed on Sundays, and in HG2 on the days with dialysis. In HG2, after 24 weeks of the nutritional intervention, an increase in serum albumin (p = 0.0157) and a decrease in CRP concentration (p = 0.0306) were observed, whereas in HG1 there was a decrease in serum albumin concentration (p = 0.0043) with no significant change in CRP concentration. The nutritional intervention applied, called the Malnutrition-Eat Additional Meal (MEAM) diet with an easily digestible meal served before dialysis, was aimed at improving the patients' nutritional status and the obtained results indicate the need not only for substantial reeducation of hemodialysis patients in the area of their diet, but also for undertaking further research and discussions on the possibility of ensuring adequate meals for hemodialysis patients before the dialysis procedure.

Feeding during Dialysis Increases Intradialytic Blood Pressure Variability and Reduces Dialysis Adequacy

Whether hemodialysis patients should be allowed or even encouraged to eat during dialysis remains a controversial topic. This cross-over study aimed to evaluate the impact of feeding during dialysis on intradialytic blood pressure (BP) profile and dialysis adequacy in 26 patients receiving thrice-weekly, in-center hemodialysis. Over three consecutive mid-week dialysis sessions, intradialytic BP was monitored using the Mobil-O-Graph device (IEM, Stolberg, Germany). Blood samples were also obtained for the determination of the urea reduction ratio (URR). At baseline, patients underwent dialysis without the provision of a meal. In phases A and B, a meal with either high-protein (1.5 gr/kg of body weight) or low-protein (0.7 gr/kg of body weight) content was administered 1 h after the initiation of dialysis. The sequence of meals (high-protein and low-protein or vice versa) was randomized. Average intradialytic systolic BP (SBP) was similar on all three occasions. However, compared with baseline, the standard deviation (SD) (11.7 ± 4.1 vs. 15.6 ± 7.6 mmHg, p < 0.01), coefficient of variation (CV) (9.5 ± 3.7% vs. 12.4 ± 6.0%, p < 0.01) and average real variability (ARV) (9.4 ± 3.9 vs. 12.1 ± 5.2 mmHg, p < 0.01) of intradialytic SBP were higher in phase A. Similarly, compared with the baseline evaluation, all three indices of intradialytic SBP variability were higher in phase B (SD: 11.7 ± 4.1 vs. 14.1 ± 4.5 mmHg, p < 0.05; CV: 9.5 ± 3.7% vs. 11.1 ± 3.8%, p < 0.05; ARV: 9.4 ± 3.9 vs. 10.9 ± 3.9 mmHg, p < 0.05). Compared with dialysis without a meal, the consumption of a high-protein or low-protein meal resulted in a lower URR (73.4 ± 4.3% vs. 65.7 ± 10.7%, p < 0.001 in phase A and 73.4 ± 4.3% vs. 67.6 ± 4.3%, p < 0.001 in phase B, respectively). In conclusion, in the present study, feeding during dialysis was associated with higher intradialytic SBP variability and reduced adequacy of the delivered dialysis.

A Comparative Study of the Efficacy of an Intervention with a Nutritional Supplement for Patients with Chronic Kidney Disease: A Randomized Trial

Chronic kidney disease (CKD) involves heterogeneous diseases that affect the renal structure and function. Malnutrition plays a crucial role during patients with CKD on hemodialysis (HD) treatment and is associated with an increased rate and duration of hospitalizations. The aim of this randomized, parallel, intervention-controlled trial was to assess whether the use of daily supplementation with a new nutritional product developed by the Grand Fontaine Laboratories improves the nutritional status and anthropometric parameters of stage 5 CKD patients, compared with standard renal dietary advice, after three months of follow-up. Dietary intake, anthropometric measurements, physical activity, and blood samples were collected at baseline and after three months of intervention. Significant improvements were observed within the intervention group in body weight (1.5 kg [95% CI: 0.9 to 2.12 kg]) and BMI (0.54 kg/m² [95% CI: 0.31 to 0.77]; p-value between groups, 0.002 and 0.006, respectively). In the control group, significant decreases were observed in transferrin saturation (-5.04% [95% CI: -8.88 to -1.21]) and alpha-tocopherol levels (-3.31 umol/L [95% CI: -6.30 to -0.32]). We concluded that daily dietary intake of a specific renal nutritional complement in CKD patients with or at risk of malnutrition may prevent deterioration in nutritional parameters.

Medical nutrition therapy using plant-focused low-protein meal plans for management of chronic kidney disease in diabetes

PURPOSE OF REVIEW

Nearly half of all Americans with chronic kidney disease (CKD) also have type-2-diabetes (T2D). Whereas traditional and emerging pharmacotherapies are increasingly frequently used for the management of CKD in diabetes (CKD/DM), the role of integrated or multimodal interventions including the potentially synergistic and additive effect of diet and lifestyle modifications in addition to pharmacotherapy has not been well examined, in sharp contrast to the well-known integrated approaches to heart disease.

RECENT FINDINGS

Low-carbohydrate low-fat diets are often recommended in T2D, whereas low-protein diets (LPD) are recommended by guidelines for nondiabetic CKD with increasing emphasis on plant-based protein sources. High-protein diets with greater animal protein lead to glomerular hyperfiltration, especially in patients with T2D, and faster decline in renal function. Guidelines provide differing recommendations regarding the amount (low vs high) and source (plant vs animal) of dietary protein intake (DPI) in CKD/DM. Some such as KDIGO recommend 0.8 g/kg/day based on insufficient evidence for DPI restriction in CKD/DM, whereas KDOQI and ISRNM recommend a DPI of 0.6 to <0.8 g/kg/day. A patient-centered plant-focused LPD for the nutritional management of CKD/DM (PLAFOND), a type of PLADO diet comprising DPI of 0.6 to <0.8 g/kg/day with >50% plant-based sources, high dietary fiber, low glycemic index, and 25-35 Cal/kg/day energy, can be implemented by renal dietitians under Medical Nutrition Therapy.

SUMMARY

Potential risks vs benefits of high vs low protein intake in CKD/DM is unknown, for which expert recommendations remain opinion based. Randomized controlled studies are needed to examine safety, acceptability and efficacy of PLAFOND.

Significance of nutrition in hemodialysis patients with peripheral arterial disease evaluated by skin perfusion pressure

Background

Peripheral artery disease (PAD) is a serious complication in hemodialysis (HD) patients. Low skin perfusion pressure (SPP) is a useful marker for detecting PAD. Malnutrition is an important cause of intractable complications. We examined the relationship between low SPP and various indicators of nutritional status.

Methods

A total of 120 patients on maintenance HD were enrolled for SPP measurement. SPP was measured at the soles of both feet during HD, and patients were divided into low SPP (L-SPP) and normal SPP (N-SPP) groups by 50 mmHg. The following values were determined by averaging four blood samples taken before SPP measurements every 3 months for one year: hemoglobin, total protein, albumin (Alb), total cholesterol, urea nitrogen, creatinine (Cr), potassium, calcium, phosphate, intact parathyroid hormone, iron (Fe), transferrin saturation (T-SAT), and C-reactive protein (CRP). We calculated the percent Cr production rate, dialysis index (Kt/V), normalized protein catabolic rate (nPCR), geriatric nutritional risk index (GNRI), and estimated salt intake using the required formulas. In addition, the age, body mass index, and presence of diabetes mellitus (DM) were compared between both groups along with all other measurements. Data were expressed as the mean ± standard deviation or median with interquartile range as appropriate. Differences in continuous variables between the two groups were analyzed by Student’s t-test or Wilcoxon’s rank-sum test, as appropriate. Multivariate logistic analysis and receiver operating curve (ROC) analysis were performed for significant variables. The results were expressed as odds ratios with respective 95% confidence intervals (CIs).

Results

The enrolled patients were 82 men and 38 women, with a mean age of 66.9 ± 13.3 years and HD duration of 4.76 (2.13–12.28) years (median interquartile range). Twenty patients belonged to the L-SPP group, suggesting PAD. Comparison between the L-SPP and N-SPP groups showed significant differences in age, Cr, Fe, T-SAT, CRP, nPCR, GNRI, DM, and estimated salt intake. When the GNRI, estimated salt intake, CRP, and DM were applied as independent variables for multiple logistic regression analysis, the GNRI (odds ratio: 0.857, 95% CI 0.781–0.941, p = 0.001), CRP (2.406, 1.051–3.980, p = 0.035), and DM (9.194, 2.497–33.853, p = 0.001) were found to be significant for L-SPP, and a cutoff level of 92.1 (sensitivity 80%, specificity 72%, AUC: 0.742, 95% CI 0.626–0.858, p = 0.001) in the GNRI obtained by ROC was consistent with the risk index in the elderly presented previously.

Conclusions

SPP measurement is an essential tool for detecting high-risk PAD in maintenance HD, which is affected by malnutrition, DM, and inflammation. The GNRI is important for the determination of malnutrition.

Amino acid removal during hemodialysis can be compensated for by protein ingestion and is not compromised by intradialytic exercise: a randomized controlled crossover trial

BACKGROUND

Patients with end-stage renal disease (ESRD) undergoing hemodialysis experience a rapid decline in skeletal muscle mass and strength. Hemodialysis removes amino acids (AAs) from the circulation, thereby lowering plasma AA concentrations and stimulating proteolysis.

OBJECTIVES

In the present study, we evaluate the impact of intradialytic protein ingestion at rest and following exercise on AA removal and plasma AA availability in patients with ESRD.

METHODS

Ten patients (age: 65 ± 16 y, male/female: 8/2, BMI: 24.2 ± 4.8 kg/m2, serum albumin: 3.4 ± 0.3 g/dL) with ESRD undergoing hemodialysis participated in this randomized controlled crossover trial. During 4 hemodialysis sessions, patients were assigned to ingest 40 g protein or a placebo 60 min after initiation, both at rest (PRO and PLA, respectively) and following exercise (PRO + EX and PLA + EX, respectively). Spent dialysate and blood samples were collected every 30 min throughout hemodialysis to assess AA removal and plasma AA availability.

RESULTS

Plasma AA concentrations declined by 26.1 ± 4.5% within 30 min after hemodialysis initiation during all interventions (P < 0.001, η2p > 0.79). Protein ingestion, but not intradialytic exercise, increased AA removal throughout hemodialysis (9.8 ± 2.0, 10.2 ± 1.6, 16.7 ± 2.2, and 17.3 ± 2.3 g during PLA, PLA + EX, PRO, and PRO + EX interventions, respectively; protein effect P < 0.001, η2p = 0.97; exercise effect P = 0.32, η2p = 0.11). Protein ingestion increased plasma AA concentrations until the end of hemodialysis, whereas placebo ingestion resulted in decreased plasma AA concentrations (time effect P < 0.001, η2p > 0.84). Plasma AA availability (incremental AUC) was greater during PRO and PRO + EX interventions (49 ± 87 and 70 ± 34 mmol/L/240 min, respectively) compared with PLA and PLA + EX interventions (-227 ± 54 and -208 ± 68 mmol/L/240 min, respectively; protein effect P < 0.001, η2p = 0.98; exercise effect P = 0.21, η2p = 0.16).

CONCLUSIONS

Protein ingestion during hemodialysis compensates for AA removal and increases plasma AA availability both at rest and during recovery from intradialytic exercise. Intradialytic exercise does not compromise AA removal or reduce plasma AA availability during hemodialysis in a postabsorptive or postprandial state.

Meal timing and frequency implications in the development and prognosis of chronic kidney disease

Patients with chronic kidney disease (CKD) have a higher risk of death than the general population, the main cause being cardiovascular disease (CVD). Nutrition plays a key role in the prevention and treatment of CVD and kidney diseases. Currently, new evidence reinforces the importance of specific foods and general dietary patterns rather than isolated nutrients for cardiovascular risk. In addition, dietary patterns and healthy eating habits seem extremely relevant in decreasing risk factors. Epidemiologic and clinical intervention studies have suggested that late-night dinner and skipping breakfast are associated with an increased risk of obesity, insulin resistance, and CVD. In CKD, despite important changes in nutritional counseling in recent decades, less attention has been paid to meal timing and frequency. Therefore, the purpose of this review is to discuss the evidence of meal timing and frequency in CKD development and prognosis, presented under three main topics: risk of developing CKD, importance of dietary habits, and implications of fasting.

How important is dietary management in chronic kidney disease progression? A role for low protein diets

High dietary protein intake may lead to increased intraglomerular pressure and glomerular hyperfiltration, which in the long-term can lead to de novo or aggravating preexisting chronic kidney disease (CKD). Hence, a low protein diet (LPD, 0.6 to 0.8 g/kg/day) is recommended for the management of CKD. There are evidences that dietary protein restriction mitigate progression of CKD and retard the initiation of dialysis or facilitate incremental dialysis. LPD is also helpful to control metabolic derangements in CKD such as metabolic acidosis and hyperphosphatemia. Recently, a growing body of evidence has emerged on the benefits of plant-dominant low-protein diet (PLADO), which composed of > 50% plant-based sources. PLADO is considered to be helpful for relieving uremic burden and metabolic complications in CKD compared to animal protein dominant consumption. It may also lead to favorable alterations in the gut microbiome, which can modulate uremic toxin generation along with reducing cardiovascular risk. Alleviation of constipation in PLADO may minimize the risk of hyperkalemia. A balanced and individualized dietary approach for good adherence to LPD utilizing various plant-based sources as patients' preference should be elaborated for the optimal care in CKD. Periodic nutritional assessment under supervision of trained dietitians should be warranted to avoid protein-energy wasting.

Protein and energy intake: Comparison of two food services in patients during hemodialysis treatment

OBJECTIVES

Radboud University Medical Center introduced a new food service (NFS) to the hemodialysis (HD) department, which contains several small protein-rich foods and adheres to the Dutch dietary HD guidelines. The objectives were to investigate whether the NFS improves protein and energy intake compared with the old food service (OFS), the number of symptomatic hypotensive events (SHEs), and patient satisfaction.

METHODS

This was a prospective cohort (pilot) study of 25 adult patients with HD at the Radboud University Medical Center between August 2018 and February 2019. Differences in protein and energy intake over time by repeated measurements of the OFS and NFS were evaluated by linear mixed models with adjustments for confounders. SHEs, defined as a systolic drop >20 mmHg between two blood pressure measurements and 1) temporary or permanent stop ultrafiltration, 2) nausea, or 3) dizziness were collected. Patient satisfaction was determined by means of a self-developed questionnaire.

RESULTS

Protein and energy intake for the OFS and NFS differed significantly. Mean ± standard deviation for protein intake was 26 ± 11 g and 31 ± 13 g, respectively, and for energy intake 603 ± 218 kcal and 724 ± 244 kcal, respectively. No increase in SHEs occurred between the food services (2 SHEs at OFS vs 1 SHE at NFS). OFS patient satisfaction was graded 6.7 ± 2.3 and NFS was graded 7.3 ± 1.7.

CONCLUSIONS

NFS resulted in increased protein and energy intake and patient satisfaction, but no increase in SHEs was observed.

Chronic Kidney Disease and Nutrition Support

Individuals with chronic kidney disease (CKD), particularly those undergoing maintenance dialysis, are prone to protein-energy wasting (PEW), the latter of which can be ameliorated with different methods of nutrition support. Dietary counseling guided by dietitians is the key for preventing and managing PEW in CKD. If dietary counseling per se fails to meet the recommended energy and protein requirements, the addition of oral nutrition supplements (ONSs) would be necessary. When these initial measures cannot attain the recommended energy and protein requirements, nutrition support, including enteral tube feeding or parenteral nutrition (PN), should be considered as a viable option to improve nutrition status. Partial PN, comprising intraperitoneal PN (IPPN) and intradialytic PN (IDPN) therapies, may be attempted as supplemental nutrition support in patients with PEW requiring peritoneal dialysis and hemodialysis, respectively. Despite the debatable effectiveness of IPPN for patients undergoing peritoneal dialysis, it remains a feasible means in these patients. The indications for IPPN in patients undergoing peritoneal dialysis include inadequate dietary intake of energy and protein, and barriers of oral intake and other forms of enteral supplementation such as issues with suitability, tolerance, and compliance. Nonetheless, in the case of spontaneous dietary consumption of energy and protein meeting the difference between the IDPN provision and the nutrition targets, the use of IDPN is rational. In patients with PEW and malfunctioning gastrointestinal tract, as well as those whose enteral intake (with or without partial PN) is below the recommended nutrient requirements, total PN becomes a relevant nutrition intervention.

Relationship of a food intake during hemodialysis and symptomatic intradialytic hypotension

INTRODUCTION

Intradialytic hypotension is the most common complication during hemodialysis and is associated with increased cardiovascular disease, mortality, and overall hospital admissions. We analyzed the influence of food intake during hemodialysis on intradialytic hypotension.

METHODS

A total of 105 patients treated with chronic hemodialysis were observed for 8 weeks-4 weeks with a meal during hemodialysis and 4 weeks without a meal.

FINDINGS

A statistically significant decrease of hypotensive events (p < 0.001) and cramping episodes (p = 0.035) was observed during a 4-week period without a meal. Patients who were particularly susceptible to intradialytic hypotension were those who were diabetic, had low urinary excretion, and were treated with hemodialysis for a long time. On a follow up, there was a significant increase in serum albumin after 3 months (p = 0.01) and 6 months (p = 0.036) despite meal withdrawal during hemodialysis.

DISCUSSION

Fasting during hemodialysis may cause a significantly lower frequency of intradialytic hypotension and cramping episodes without affecting the nutritional status.

Slipping Through the Pores: Hypoalbuminemia and Albumin Loss During Hemodialysis

Hypoalbuminemia results when compensatory mechanisms are unable to keep pace with derangements in catabolism/loss and/or decreased synthesis of albumin. Across many disease states, including chronic kidney disease (CKD), hypoalbuminemia is a well-established, independent risk factor for adverse outcomes, including mortality. In the setting of CKD, reduced serum albumin concentrations are often a manifestation of protein-energy wasting, a state of metabolic and nutritional alterations resulting in reduced protein and energy stores. The progression of CKD to kidney failure and the initiation of maintenance hemodialysis (HD) further predisposes an already at-risk population toward hypoalbuminemia such that approximately 60% of HD patients have albumin concentrations <4.0 g/dl. Albumin loss into the dialysate through the dialyzer appears to be a potentially modifiable cause of hypoalbuminemia in some patients. A group of newer dialyzers for maintenance HD-sometimes termed protein-leaking or medium cut-off membranes-aim to improve clearance of middle molecules (vs high flux dialyzers) but are associated with increased albumin losses. In this article, we will examine the impact of dialyzer selection on albumin losses during conventional HD, including the clinical relevance of such losses on serum albumin levels. Data on the clinical relevance of albumin losses during dialysis and current gaps in the evidence base are also discussed.

Nutrition-Based Management of Inflammaging in CKD and Renal Replacement Therapies

Access to renal transplantation guarantees a substantial improvement in the clinical condition and quality of life (QoL) for end-stage renal disease (ESRD) patients. In recent years, a greater number of older patients starting renal replacement therapies (RRT) have shown the long-term impact of conservative therapies for advanced CKD and the consequences of the uremic milieu, with a frail clinical condition that impacts not only their survival but also limits their access to transplantation. This process, referred to as “inflammaging,” might be reversible with a tailored approach, such as RRT accompanied by specific nutritional support. In this review, we summarize the evidence demonstrating the presence of several proinflammatory substances in the Western diet (WD) and the positive effect of unprocessed food consumption and increased fruit and vegetable intake, suggesting a new approach to reduce inflammaging with the improvement of ESRD clinical status. We conclude that the Mediterranean diet (MD), because of its modulative effects on microbiota and its anti-inflammaging properties, may be a cornerstone in a more precise nutritional support for patients on the waiting list for kidney transplantation.

An update review of intradialytic hypotension: concept, risk factors, clinical implications and management

Intradialytic hypotension (IDH) is a frequent and serious complication of chronic haemodialysis, linked to adverse long-term outcomes including increased cardiovascular and all-cause mortality. IDH is the end result of the interaction between ultrafiltration rate (UFR), cardiac output and arteriolar tone. Thus excessive ultrafiltration may decrease the cardiac output, especially when compensatory mechanisms (heart rate, myocardial contractility, vascular tone and splanchnic flow shifts) fail to be optimally recruited. The repeated disruption of end-organ perfusion in IDH may lead to various adverse clinical outcomes affecting the heart, central nervous system, kidney and gastrointestinal system. Potential interventions to decrease the incidence or severity of IDH include optimization of the dialysis prescription (cool dialysate, UFR, sodium profiling and high-flux haemofiltration), interventions during the dialysis session (midodrine, mannitol, food intake, intradialytic exercise and intermittent pneumatic compression of the lower limbs) and interventions in the interdialysis period (lower interdialytic weight gain and blood pressure–lowering drugs). However, the evidence base for many of these interventions is thin and optimal prevention and management of IDH awaits further clinical investigation. Developing a consensus definition of IDH will facilitate clinical research. We review the most recent findings on risk factors, pathophysiology and management of IDH and, based on this, we call for a new consensus definition of IDH based on clinical outcomes and define a roadmap for IDH research.

Plant-Dominant Low-Protein Diet for Conservative Management of Chronic Kidney Disease

Chronic kidney disease (CKD) affects >10% of the adult population. Each year, approximately 120,000 Americans develop end-stage kidney disease and initiate dialysis, which is costly and associated with functional impairments, worse health-related quality of life, and high early-mortality rates, exceeding 20% in the first year. Recent declarations by the World Kidney Day and the U.S. Government Executive Order seek to implement strategies that reduce the burden of kidney failure by slowing CKD progression and controlling uremia without dialysis. Pragmatic dietary interventions may have a role in improving CKD outcomes and preventing or delaying dialysis initiation. Evidence suggests that a patient-centered plant-dominant low-protein diet (PLADO) of 0.6–0.8 g/kg/day composed of >50% plant-based sources, administered by dietitians trained in non-dialysis CKD care, is promising and consistent with the precision nutrition. The scientific premise of the PLADO stems from the observations that high protein diets with high meat intake not only result in higher cardiovascular disease risk but also higher CKD incidence and faster CKD progression due to increased intraglomerular pressure and glomerular hyperfiltration. Meat intake increases production of nitrogenous end-products, worsens uremia, and may increase the risk of constipation with resulting hyperkalemia from the typical low fiber intake. A plant-dominant, fiber-rich, low-protein diet may lead to favorable alterations in the gut microbiome, which can modulate uremic toxin generation and slow CKD progression, along with reducing cardiovascular risk. PLADO is a heart-healthy, safe, flexible, and feasible diet that could be the centerpiece of a conservative and preservative CKD-management strategy that challenges the prevailing dialysis-centered paradigm.

Eating during the Hemodialysis Session: A Practice Improving Nutritional Status or a Risk Factor for Intradialytic Hypotension and Reduced Dialysis Adequacy?

Historically, eating during the hemodialysis treatment has been associated with increased risk for adverse intradialytic symptoms and events, risks that have resulted in the implementation of restrictive in-center nutrition policies. Recent studies, however, have recorded a shift in clinical practice with a higher proportion of physicians following the view that administration of intradialytic meals and supplements represents a simple and effective approach to enhance caloric intake and improve nutritional status among patients on hemodialysis. This shift towards less restrictive in-center nutrition practices is mainly supported by evidence from observational studies associating intradialytic nutritional supplementation with improvements in protein-energy wasting, inflammatory state, and health-related quality of life. In sharp contrast, earlier and recent interventional studies have documented that feeding during the hemodialysis treatment provokes a rapid postprandial decline in blood pressure and raises the incidence of symptomatic intradialytic hypotension. Furthermore, other studies have shown that postprandial redistribution in intravascular volume and enhanced blood supply to the gastrointestinal circulation may interfere with the adequacy of the delivered hemodialysis. Those who defend the position that intradialytic nutritional support is beneficial do not dispute the physiology of postprandial hemodynamic response, but they argue against its clinical significance. In this article, we provide an overview of studies that explored the effect of eating during the hemodialysis treatment on intradialytic hemodynamic stability and adequacy of the delivered hemodialysis. We reason that these risks have important clinical implications that are not counteracted by anticipated benefits of this strategy on caloric intake and nutritional status.

Intradialytic Nutrition and Hemodialysis Prescriptions: A Personalized Stepwise Approach

Dialysis and nutrition are two sides of the same coin—dialysis depurates metabolic waste that is typically produced by food intake. Hence, dietetic restrictions are commonly imposed in order to limit potassium and phosphate and avoid fluid overload. Conversely, malnutrition is a major challenge and, albeit to differing degrees, all nutritional markers are associated with survival. Dialysis-related malnutrition has a multifactorial origin related to uremic syndrome and comorbidities but also to dialysis treatment. Both an insufficient dialysis dose and excessive removal are contributing factors. It is thus not surprising that dialysis alone, without proper nutritional management, often fails to be effective in combatting malnutrition. While composite indexes can be used to identify patients with poor prognosis, none is fully satisfactory, and the definitions of malnutrition and protein energy wasting are still controversial. Furthermore, most nutritional markers and interventions were assessed in hemodialysis patients, while hemodiafiltration and peritoneal dialysis have been less extensively studied. The significant loss of albumin in these two dialysis modalities makes it extremely difficult to interpret common markers and scores. Despite these problems, hemodialysis sessions represent a valuable opportunity to monitor nutritional status and prescribe nutritional interventions, and several approaches have been tried. In this concept paper, we review the current evidence on intradialytic nutrition and propose an algorithm for adapting nutritional interventions to individual patients.

Dietary Protein and Physical Activity Interventions to Support Muscle Maintenance in End-Stage Renal Disease Patients on Hemodialysis

End-stage renal disease patients have insufficient renal clearance capacity left to adequately excrete metabolic waste products. Hemodialysis (HD) is often employed to partially replace renal clearance in these patients. However, skeletal muscle mass and strength start to decline at an accelerated rate after initiation of chronic HD therapy. An essential anabolic stimulus to allow muscle maintenance is dietary protein ingestion. Chronic HD patients generally fail to achieve recommended protein intake levels, in particular on dialysis days. Besides a low protein intake on dialysis days, the protein equivalent of a meal is extracted from the circulation during HD. Apart from protein ingestion, physical activity is essential to allow muscle maintenance. Unfortunately, most chronic HD patients have a sedentary lifestyle. Yet, physical activity and nutritional interventions to support muscle maintenance are generally not implemented in routine patient care. To support muscle maintenance in chronic HD patients, quantity and timing of protein intake should be optimized, in particular throughout dialysis days. Furthermore, implementing physical activity either during or between HD sessions may improve the muscle protein synthetic response to protein ingestion. A well-orchestrated combination of physical activity and nutritional interventions will be instrumental to preserve muscle mass in chronic HD patients.

Feeding during dialysis-risks and uncertainties

Allowing dialysis patients to eat during the treatment is controversial. It is, therefore, no surprise that practices and policies with respect to intradialytic food consumption vary considerably from unit to unit and from country to country. Those who defend the position of feeding during dialysis reason that intradialytic meals offer a supervised and effective therapy for protein-energy wasting. Those who take the opposite view argue that intradialytic food intake should be avoided for the following three reasons. First, interventional studies show that eating during dialysis causes a clinically significant reduction in systemic blood pressure during the postprandial period and elevates the risk of symptomatic intradialytic hypotension; the latter is associated with increased mortality risk. Second, clinical studies have shown that eating during dialysis interferes with the adequacy of the delivered dialysis, whereas eating 2-3 h before the dialysis session has no impact on the efficiency of the subsequent dialysis treatment. And third, randomized studies show that eating during dialysis focus on the positive outcomes but do not adequately balance this potential benefit against the risk of intradialytic hemodynamic instability and poor quality of delivered dialysis. Even after half a century of providing long-term dialysis, definitive randomized trials that balance risks and benefits of eating during dialysis are missing. These knowledge gaps require randomized trials. Since there is a real possibility of harm with eating during dialysis, we caution that instead of encouraging the widespread use of intradialytic meals, practices and policies should focus on adequate nutrient intake during the interdialytic interval.

The role of phosphate-containing medications and low dietary phosphorus-protein ratio in reducing intestinal phosphorus load in patients with chronic kidney disease

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is a common complication in patients experiencing end-stage renal disease (ESRD). It includes abnormalities in bone and mineral metabolism and vascular calcification. Hyperphosphatemia is a major risk factor leading to morbidity and mortality in patients with chronic kidney disease. Increased mortality has been observed in patients with ESRD, with serum phosphorus levels of >5.5 mg/dL. Therefore, control of hyperphosphatemia is a major therapeutic goal in the prevention and treatment of CKD-MBD. The treatment of hyperphosphatemia includes decreasing intestinal phosphorus load and increasing renal phosphorus removal. Decreasing the intestinal load of phosphorus plays a major role in the prevention and treatment of CKD-MBD. Among the dietary sources of phosphorus, some of the commonly prescribed medications have also been reported to contain phosphorus. However, drugs are often ignored even though they act as a potential source of phosphorus. Similarly, although proteins are the major source of dietary phosphorus, reducing protein intake can increase mortality in patients with CKD. Recently, the importance of phosphorus/protein ratio in food have been reported to be a sensitive marker for controlling dietary intake of phosphorus. This review summarizes the progress in the research on phosphate content in drugs as an excipient and the various aspects of dietary management of hyperphosphatemia in patients with CKD, with special emphasis on dietary restriction of phosphorus with low dietary phosphate/protein ratio.

Patients' perceptions of their experience, control and knowledge of fluid management when receiving haemodialysis

BACKGROUND

Person-centred care is increasingly promoted, empowering patients to become more involved in their treatment rather than being passive recipients of care (Barnes et al. 2013). Haemodialysis is typically required three times a week, with fluid management decision-making occurring at each treatment session (Ahmed et al. 2017). However, no research has yet explored how haemodialysis patients' perceptions of their fluid management may impact upon this decision-making.

OBJECTIVES

This study sought to explore patients' perceptions of their fluid management.

METHOD

DESIGN, PARTICIPANTS & APPROACH: Semi-structured interviews were conducted with 12 patients undergoing in-hospital haemodialysis treatment. These were digitally recorded one-to-one interviews to allow for verbatim transcription. The data was analysed by thematic analysis, generating thematic patterns across patients' experiences, control and knowledge of their fluid management.

RESULTS

Five themes were produced: determining who has the expertise, impediments affecting patients' lifestyle, additional difficulty of experiencing comorbidities, perceived quality of care, and establishing consistency.

CONCLUSIONS

Despite varied levels of patient participation in their treatment, overall there appears to be a limited understanding of specific areas of fluid management. The implications for further research and the development of shared-care are discussed.

Insulin resistance is a significant determinant of sarcopenia in advanced kidney disease

Maintenance hemodialysis (MHD) patients display significant nutritional abnormalities. Insulin is an anabolic hormone with direct effects on skeletal muscle (SM). We examined the anabolic actions of insulin, whole-body (WB), and SM protein turnover in 33 MHD patients and 17 participants without kidney disease using hyperinsulinemic-euglycemic-euaminoacidemic (dual) clamp. Gluteal muscle biopsies were obtained before and after the dual clamp. At baseline, WB protein synthesis and breakdown rates were similar in MHD patients. During dual clamp, controls had a higher increase in WB protein synthesis and a higher suppression of WB protein breakdown compared with MHD patients, resulting in statistically significantly more positive WB protein net balance [2.02 (interquartile range [IQR]: 1.79 and 2.36) vs. 1.68 (IQR: 1.46 and 1.91) mg·kg fat-free mass^-1·min^-1 for controls vs. for MHD patients, respectively, P < 0.001]. At baseline, SM protein synthesis and breakdown rates were higher in MHD patients versus controls, but SM net protein balance was similar between groups. During dual clamp, SM protein synthesis increased statistically significantly more in controls compared with MHD patients ( P = 0.03), whereas SM protein breakdown decreased comparably between groups. SM net protein balance was statistically significantly more positive in controls compared with MHD patients [67.3 (IQR: 46.4 and 97.1) vs. 15.4 (IQR: -83.7 and 64.7) μg·100 ml^-1·min^-1 for controls and MHD patients, respectively, P = 0.03]. Human SM biopsy showed a positive correlation between glucose and leucine disposal rates, phosphorylated AKT to AKT ratio, and muscle mitochondrial markers in controls but not in MHD patients. Diminished response to anabolic actions of insulin in the stimulated setting could lead to muscle wasting in MHD patients.

Accuracy of a Nutrient Database in Estimating the Dietary Phosphorus-to-Protein Ratio and Using a Boiling Method in Low-Phosphate Hospital Diets

The use of the dietary phosphorus-to-protein ratio (PPR) to reduce dietary phosphorus while maintaining protein intake is valuable for nutritional management in the dialysis population, but the actual PPR values in hospital meals have not been determined. We aimed to determine the accuracy of a nutrient database for estimating the PPR in low-phosphate hospital diets compared with the accuracy of chemical analysis and produce hospital diets with low-phosphate content by boiling meat for 30 minutes before cooking. The phosphorus and protein content of 26 cooked dishes selected from the hospital menu was estimated using a food composition table (FCT) and sent for chemical analysis. Comparisons of FCT-based estimated values with measured values for every 100 g of tested foods revealed an overestimation for the PPR both in plant-based dishes (mean difference ± SD, 4.1 ± 14.6 mg/g, P = 0.06), and in meats (2.1 ± 2.3 mg/g, P = 0.06). By boiling meats, we crafted diets with PPR as low as 8 mg/g. Caution should be exercised in estimating the PPR using a FCT in hospital diets and boiling should be used to prepare hospital meals. Such diets will be promoted for dialysis patients in both inpatient and outpatient settings.

The effects of oral nutritional supplements in patients with maintenance dialysis therapy: A systematic review and meta-analysis of randomized clinical trials

Background/objective

This systematic review aims to determine the potential effects of oral nutritional supplements (ONS) in patients receiving maintenance dialysis therapy (MDT).

Methods

Electronic databases were searched without language limits through to July 2018. Randomized controlled trials (RCTs) that involved comparisons of ONS versus placebo or routine care are included in this meta-analysis. RevMan 5.3 statistical software was used for meta-analysis.

Results

15 articles with 589 subjects were included in our study. There are insufficient comparable data of randomized trials to allow meta-analysis of mortality. Albumin levels may be improved by the macronutrient blends or protein/amino acid supplements in MDT patients. Compared with the control group, serum albumin levels and BMI in the ONS group were increased by 1.58 g/L (95% CI, 0.52–2.63, P = 0.003; I² = 85%) and 0.40 kg/m² (95% CI, 0.10–0.71, P = 0.01; I² = 49%), respectively. In the subgroup analysis of patients receiving hemodialysis, albumin levels in ONS group were increased by 2.17 g/L (95% CI, 0.89–3.45, P<0.001; I² = 90%). ONS may not influence serum phosphorus and potassium levels.

Conclusions

Very low-quality evidence suggests that Short-term oral energy or protein/amino acid supplements may improve nutritional status by increasing serum albumin levels and BMI in MDT patients, without influence on serum potassium levels. High-quality and large RCTs, particularly regarding the effects of ONS on mortality and quality of life, are needed to further validate our findings.

Dietary Practice among the Patients with End Stage Renal Disease undergoing Maintenance Haemodialysis

INTRODUCTION

Several studies on the nutritional status of chronic kidney disease patients living on haemodialysis revealed high prevalence of malnutrition (18-94%). A hospital-based study in Nepal revealed 66.7% mild to moderately malnourished and National Kidney Center reported common protein-energy malnutrition problem among haemodialysis patients. As almost all patients undergoing maintenance haemodialysis looked malnourished, this study was carried out to explore prevailing dietary knowledge and practice of the patients.

METHODS

A descriptive cross-sectional survey of 471 patients undergoing haemodialysis from June 2015 to July in 2015 was carried out. After stratification through a systematic random sampling method, 40 (67%) patients from National Kidney Center and 20 (33%) from Bir Hospital were selected, interviewed face to face by using structured questionnaire. Ethical and institutional approval and patients' consent were obtained.

RESULTS

The level of knowledge score found to be medium and practice score was even low. Seventy percent knew about renal diet but only 36 (60%) believed in it. After having kidney disease 42 (70%) had changed their dietary practice. Surprisingly, 38 (63.3%) said they ate the food what the other member in their family ate.

CONCLUSIONS

Considerable limited knowledge (medium) and practices (low) scores were found. Had they have taken adequate dietician's support, they might have taken right kind and right amounts of foods and benefitted in controlling potassium, phosphate and protein at the recommended level. Plant-based diet could assist in end stage renal disease in a number of ways: an edge of protection against diet cost, reduce inter-related co-morbidities or complications (hypertension and diabetes).

Dysregulated Handling of Dietary Protein and Muscle Protein Synthesis After Mixed-Meal Ingestion in Maintenance Hemodialysis Patients

Introduction

Skeletal muscle loss is common in patients with renal failure who receive maintenance hemodialysis (MHD) therapy. Regular ingestion of protein-rich meals are recommended to help offset muscle protein loss in MHD patients, but little is known about the anabolic potential of this strategy.

Methods

Eight MHD patients (age: 56 ± 5 years; body mass index [BMI]: 32 ± 2 kg/m²) and 8 nonuremic control subjects (age: 50 ± 2 years: BMI: 31 ± 1 kg/m²) received primed continuous L-[ring-²H₅]phenylalanine and L-[1-¹³C]leucine infusions with blood and muscle biopsy sampling on a nondialysis day. Participants consumed a mixed meal (546 kcal; 20-g protein, 59-g carbohydrates, 26-g fat) with protein provided as L-[5,5,5-²H₃]leucine-labeled eggs.

Results

Circulating dietary amino acid availability was reduced in MHD patients (41 ± 5%) versus control subjects (61 ± 4%; P = 0.03). Basal muscle caspase-3 protein content was elevated (P = 0.03) and large neutral amino acid transporter 1 (LAT1) protein content was reduced (P = 0.02) in MHD patients versus control subjects. Basal muscle protein synthesis (MPS) was ∼2-fold higher in MHD patients (0.030 ± 0.005%/h) versus control subjects (0.014 ± 0.003%/h) (P = 0.01). Meal ingestion failed to increase MPS in MHD patients (absolute change from basal: 0.0003 ± 0.007%/h), but stimulated MPS in control subjects (0.009 ± 0.002%/h; P = 0.004).

Conclusions

MHD patients demonstrated muscle anabolic resistance to meal ingestion. This blunted postprandial MPS response in MHD patients might be related to high basal MPS, which results in a stimulatory ceiling effect and/or reduced plasma dietary amino acid availability after mixed-meal ingestion.

Pilot Study of the Effects of High-Protein Meals During Hemodialysis on Intradialytic Hypotension in Patients Undergoing Maintenance Hemodialysis

OBJECTIVE

Patients undergoing hemodialysis (HD) have high protein and energy requirements, and protein-energy wasting is common and associated with poor outcomes. Eating during dialysis may improve nutritional status by counteracting the catabolic effects of HD treatment; but eating during HD may be discouraged because of concerns of postprandial hypotension. However, little data are available to support this practice. In this study, we hypothesized that high-protein meals during HD do not lead to symptomatic intradialytic hypotension events.

DESIGN

A 9-week, nonrandomized, parallel-arm study.

SETTING

A single in-center HD clinic.

SUBJECTS

Eighteen patients undergoing HD from 2 shifts completed the study. Patients were aged 62 ± 16 years with dialysis vintage of 3.4 ± 2.6 years.

INTERVENTION

Patients in the intervention group (n = 9) undergoing HD received meals of ∼30 g protein and ∼1/3 daily recommended intakes of sodium, potassium, phosphorus, and fluid during dialysis for 25 consecutive HD sessions. The control group (n = 9) completed all aspects of the study including a visit by study personnel but were not given meals. The 25 consecutive sessions before the start of the intervention/control phase were used as a baseline comparison for each patient.

MAIN OUTCOME MEASURE

Symptomatic hypotension event frequency.

RESULTS

In the intervention arm, there were 19 symptomatic hypotension events in 5 patients prestudy and 18 events in 6 patients during the study. In the control arm, there were 16 events in 7 patients prestudy and 13 events in 7 patients during the study. Change in the frequency of symptomatic hypotension events from prestudy to during study was not different between groups (P = .71). There was no effect of meals on nutritional status, but patients reported positive attitudes toward receiving meals during dialysis.

CONCLUSION

High-protein meals during HD did not increase symptomatic hypotension events. Larger, longer term studies are needed to confirm these results and evaluate whether high-protein meals on dialysis benefit nutritional status and clinical outcomes.

Is Dietary Protein Intake Predictive of 1-Year Mortality in Dialysis Patients?

BACKGROUND

High mortality in dialysis patients may be associated with protein-energy wasting (PEW) syndrome characterized by progressively depleted protein and energy stores. While early diagnosis and treatment of PEW can reduce mortality, clinically practical measures for its detection are lacking. Poor dietary protein intake (DPI) is associated with risk of malnutrition and PEW. However, the impact of DPI on mortality is unclear. The purpose of this study is to examine the ability of DPI to predict 1-year mortality in dialysis patients.

METHODS

This prospective, secondary study using data from the Comprehensive Dialysis Study and United States Renal Data System examined risk factors associated with 1-year mortality in dialysis patients.

RESULTS

Seventeen (7.5%) of the 227 subjects died within 1 year following baseline data collection. One year survivors were significantly younger (60 ± 13.6 versus 71 ± 12.8; P = 0.0043), had a lower Charlson Comorbidity Index score (1.6 ± 2.3 versus 4.0 ± 3.6; P = 0.0157), higher serum albumin level (3.5 ± 0.5 versus 3.3 ± 0.4; P = 0.0173) and had higher DPI (63 ± 33.7 versus 49.5 ± 21.5 g/day; P = 0.0386) than those who died. In multivariable Cox proportional hazards model analyses, only the Charlson Comorbidity Index adjusted hazard ratio for death (1.24) was significantly associated with increased mortality. The Comprehensive Dialysis Study data showed no association between DPI and 1-year mortality in dialysis patients.

CONCLUSIONS

Future studies using more precise measures should further examine the impact of DPI on mortality given the known association of DPI with PEW syndrome and the definitive link between PEW syndrome and survival in dialysis patients.

Is Nutrition Specific Quality of Life Associated With Nutritional Status?

OBJECTIVE

The study purpose was to explore the relationship between nutritional status, as measured by Subjective Global Assessment (SGA), and Health Related Quality of Life measured using the Nutrition Specific Quality of Life (NS-QoL), tool among participants on maintenance hemodialysis (MHD). The study aim was to determine if NS-QoL may be an adjuvant tool for detecting changes in nutritional status among patients on MHD.

DESIGN, SETTING, AND SUBJECTS

This is a cross-sectional, secondary analysis of data from a multi-center study. Participants were adult (>18) men and women on MHD (n = 145) recruited from 3 institutions in the Northeastern United States.

METHODS

Statistical tests were conducted to determine the relationship between key demographic characteristics (age, sex, dialysis vintage, gender, and ethnicity) and SGA and NS-QoL. Spearman's correlation examined the relationship between the independent variable, SGA and the dependent variable, NS-QoL. A univariate general linear model was conducted to adjust for confounding variables.

MAIN OUTCOME MEASURE

The relationship between overall SGA score and composite NS-QoL score.

RESULTS

The sample consisted of 85 men (58.6%), with a mean age of 55.3 ± 11.9 years, who were largely African-American (84.1%) and non-Hispanic (77.2%). Mean SGA score was 5.5 ± 1.0, and the mean NS-QoL composite score was 9.51 ± 3.77. No key demographic characteristics had a statistically significant relationship with SGA, whereas sex (P < .001) and race (P = .015) both had statistically significant relationships with NSQoL. After adjusting for the variables of race and sex, NS-QoL score was positively correlated with SGA composite score (P = .042); as NS-QoL score increased so did the SGA score.

CONCLUSION

The present study found a positive linear correlation between NS-QoL composite score and SGA, as well as 5 SGA subcomponent scores and NS-QoL. These findings indicate that NS-QoL can complement the SGA to provide information about a patient's nutritional status.

Effect of high-protein meals during hemodialysis combined with lanthanum carbonate in hypoalbuminemic dialysis patients: findings from the FrEDI randomized controlled trial

Background

Inadequate protein intake and hypoalbuminemia, indicators of protein-energy wasting, are among the strongest mortality predictors in hemodialysis patients. Hemodialysis patients are frequently counseled on dietary phosphorus restriction, which may inadvertently lead to decreased protein intake. We hypothesized that, in hypoalbuminemic hemodialysis patients, provision of high-protein meals during hemodialysis combined with a potent phosphorus binder increases serum albumin without raising phosphorus levels.

Methods

We conducted a randomized controlled trial in 110 adults undergoing thrice-weekly hemodialysis with serum albumin <4.0 g/dL recruited between July 2010 and October 2011 from eight Southern California dialysis units. Patients were randomly assigned to receive high-protein (50-55 g) meals during dialysis, providing 400-500 mg phosphorus, combined with lanthanum carbonate versus low-protein (<1 g) meals during dialysis, providing <20 mg phosphorus. Prescribed nonlanthanum phosphorus binders were continued over an 8-week period. The primary composite outcome was a rise in serum albumin of ≥0.2 g/dL while maintaining phosphorus between 3.5-<5.5 mg/dL. Secondary outcomes included achievement of the primary outcome's individual endpoints and changes in mineral and bone disease and inflammatory markers.

Results

Among 106 participants who satisfied the trial entrance criteria, 27% ( n = 15) and 12% ( n = 6) of patients in the high-protein versus low-protein hemodialysis meal groups, respectively, achieved the primary outcome (intention-to-treat P-value = 0.045). A lower proportion of patients in the high-protein versus low-protein intake groups experienced a meaningful rise in interleukin-6 levels: 9% versus 31%, respectively (P = 0.009). No serious adverse events were observed.

Conclusion

In hypoalbuminemic hemodialysis patients, high-protein meals during dialysis combined with lanthanum carbonate are safe and increase serum albumin while controlling phosphorus.

The Relationship Between Intradialytic Nutrition and Gastrointestinal Symptoms Using a Modified Version of the Gastrointestinal Symptom Rating Scale

OBJECTIVE

Intradialytic nutrition has been shown to improve nutritional status in maintenance hemodialysis (HD) patients but remains controversial due in part to concerns over hemodynamic stability and gastrointestinal (GI) distress. There are limited data on the relationship between intradialytic nutrition and GI symptoms, possibly due to the lack of a validated tool. Therefore, we intended to validate a questionnaire to measure GI symptoms associated with a single HD treatment and determine the relationship between intradialytic nutrition and GI symptoms.

DESIGN

Cross-sectional study. Forty-eight maintenance HD patients.

MAIN OUTCOME MEASURE

GI symptoms and dietary intake during HD treatment.

RESULTS

In general, we found acceptable internal consistency (Cronbach's alpha >0.5, exception reflux domain) and repeatability in all 5 domains of a modified version of the Gastrointestinal Symptom Rating Scale. The prevalence of GI symptoms associated with a single HD treatment (generalized score greater than 1) was 54.2, 43.7, 6.2, 41.7, and 45.8% for the abdominal pain, indigestion, reflux, diarrhea, and constipation domains, respectively. More than two-thirds of patients chose to eat during treatment (168.6 ± 165.6 kcal) with the most commonly consumed items being candy, oral supplements, and cookies. There was no difference in GI symptoms among patients who did or did not eat (P > .05). However, the amount of total dietary fat and fiber consumed during treatment was associated with greater indigestion (P < .05) prior to accounting for outliers or multiple comparisons.

CONCLUSION

In this sample, the modified version of the Gastrointestinal Symptom Rating Scale was a generally valid tool for measuring GI symptoms associated with a single HD treatment. Patients who ate during treatment did not experience greater GI symptoms than those who did not; however, high amounts of fat and fiber may be associated with greater GI symptoms. Prospective trials should examine the relationship between GI symptoms and dietary intake during treatment in HD patients.

Intensified treatment of hyperphosphatemia associated with reduction in parathyroid hormone in patients on maintenance hemodialysis

Background: This study investigated the therapeutic effect of intensive phosphorus-lowering therapy on intact-parathyroid hormone (iPTH) levels in hemodialysis patients.

Methods: Ninety-five hemodialysis patients with serum phosphorus ≥1.78 mmol/L and iPTH ≥300 pg/dL were apportioned to either the treatment or control group (n = 43 and 52, respectively) based on patient commitment to treatment. The treatment group was given phosphorus-lowering therapies with phosphate binders (lanthanum, sevelamer or/and calcium reagent) combined with dietary phosphate restriction and intensified hemodialysis. The control individuals were given low doses of calcium agents, if serum calcium was <2.54 mmol/L. Percent changes in serum phosphorus and iPTH levels were compared between the two groups. In addition, based on the time required to achieve >20% decrease in serum phosphorus, the patients in the treatment group were further stratified as rapid responders (≤2 months; 27 patients) or slow responders (>2 months; 16 patients) and percent changes in iPTH were compared.

Results: Serum phosphorus and iPTH levels decreased from baseline in the treatment group (−24.08 ± 1.93% and −9.92 ± 3.70%, respectively) but increased in the control group (22.00 ± 3.63% and 104.21 ± 23.89%; both p < .001). In the rapid responders subgroup, the iPTH decreased (−16.93 ± 3.49%), but in the slow responders subgroup the iPTH increased slightly (0.68 ± 7.37%, p < .05).

Conclusions: For these patients on maintenance hemodialysis, intensive treatment of hyperphosphatemia was associated with a decrease in iPTH levels, especially for those who had achieved substantial reduction in serum phosphorus within 2 months.

Children tolerate intradialytic oral nutrition

BACKGROUND

People undergoing haemodialysis (HD) often have poor nutrition, which in turn can contribute to worse outcomes. Inadequate nutrition has a particularly deleterious effect on growth and neurocognitive development, as well as mortality, in children and adolescents. Nutritional supplementation can improve outcomes but can be difficult to administer.

OBJECTIVE

Determine the tolerability of intradialytic oral nutrition in children and adolescents.

DESIGN

A cross-sectional quality improvement study in an outpatient paediatric HD unit. Intervention was intradialytic oral nutritional supplementation provided as protein bars and/or meals.

SUBJECTS

Children and adolescents undergoing outpatient HD who were able to participate in surveys and eat by mouth.

MEASUREMENTS

Adverse effects and symptoms on nurse- and patient-reported surveys, respectively. Relationships between the predictor variables and the outcomes were assessed using generalised estimating equations.

RESULTS

The majority of children felt better after eating on dialysis (72%) with no adverse effects (80%). On unadjusted analyses and confirmed with generalised estimating equation modelling, children who reported being hungry felt better after eating on dialysis, despite being more likely to have adverse effects.

CONCLUSION

The study demonstrates that our children and adolescents feel better after eating on HD with minimal adverse effects. The finding that hungry patients are more likely to feel better despite having a higher likelihood of an adverse effect demonstrates the tolerability of eating on HD. Intradialytic oral nutrition could be a safe and well-tolerated opportunity to provide supplemental nutrition to paediatric HD patients and improve outcomes.

Effects of Oral Nutritional Supplements on Mortality, Missed Dialysis Treatments, and Nutritional Markers in Hemodialysis Patients

OBJECTIVE

Protein-energy wasting is common in end-stage renal disease patients undergoing dialysis and is strongly associated with mortality and adverse outcomes. Intradialytic oral nutritional supplements (ONS) reduce risk of mortality in these patients. Large studies characterizing the impact of ONS on other outcomes are lacking. We assessed the associations between administration of ONS and clinical and nutritional outcomes.

DESIGN

Retrospective evaluation of a pilot program providing ONS to patients at a large dialysis organization in the United States. The pilot program provided ONS to in-center hemodialysis patients with serum albumin ≤3.5 g/dL at 408 facilities.

SUBJECTS

ONS patients were compared to matched controls with serum albumin ≤3.5 g/dL, identified from facilities not participating in the ONS program (n = 3,374 per group).

INTERVENTION

Receipt of ONS.

MAIN OUTCOME MEASURES

Death, missed dialysis treatments, hospitalizations, serum albumin, normalized protein catabolic rate, and postdialysis body weight were abstracted from large dialysis organization electronic medical records.

RESULTS

There was a 69% reduction in deaths (hazard ratio = 0.31; 95% confidence interval = 0.25-0.39), and 33% fewer missed dialysis treatments (incidence rate ratio = 0.77; 95% confidence interval = 0.73-0.82) among ONS patients compared to controls (P < .001 for both). The effects of ONS on nutritional indices were mixed: serum albumin was lower, whereas normalized protein catabolic rate values, a surrogate for dietary protein intake, and postdialysis body weights were higher for ONS patients compared to controls during follow-up.

CONCLUSIONS

Our evaluation confirmed the beneficial effects of ONS in reducing mortality and improving some indices of nutritional status for hypoalbuminemic hemodialysis patients. We also report the novel finding that ONS can reduce the number of missed dialysis treatments. These results support the use of intradialytic ONS as an effective intervention to improve the outcomes in hemodialysis patients with low serum albumin.

Nutritional parameters as mortality predictors in haemodialysis: Differences between genders

BACKGROUND

Malnutrition is common in patients undergoing haemodialysis (HD). Several studies have described different nutritional parameters as mortality predictors but few have studied whether there are differences between genders. This study aimed to evaluate which nutrition parameters may be associated with mortality in patients undergoing long-term HD depending on their gender.

METHODS

Longitudinal prospective multicentre study with 12 months of follow-up. Anthropometric and laboratory measures were obtained from 697 patients.

RESULTS

Men who died were older, had lower dry weight, body mass index, potassium, phosphorus and albumin, compared with male patients who survived. Female patients who died had lower albumin and nPCR compared with survivors. Kaplan-Meier analysis displayed a significantly worse survival in patients with albumin <3.5 g/dl in both genders and with body mass index <23 kg/m² in men. In the Cox regression analysis patients overall mortality was related to body mass index <23 kg/m² , potassium ≤5.5 mEq/l and phosphorus <3.0 mg/dl for male patients and albumin <3.5 g/dl and normalised protein catabolic rate (nPCR) <0.8 g/kg/day for both genders. Associations between albumin, body mass index and mortality risk continued to be significant after adjustments for age, length of time on dialysis and diabetes for males. However, in women, only albumin persisted as an independent predictor of death.

CONCLUSION

Depending on the gender, different parameters such as protein intake, potassium, phosphorus, body mass index and albumin are associated with mortality in patients undergoing HD. Albumin <3.5 g/dl is an independent mortality predictor in both genders, whereas a body mass index <23 kg/m² is an independent predictor of death, but only in men.

The Diet and Haemodialysis Dyad: Three Eras, Four Open Questions and Four Paradoxes. A Narrative Review, Towards a Personalized, Patient-Centered Approach

The history of dialysis and diet can be viewed as a series of battles waged against potential threats to patients' lives. In the early years of dialysis, potassium was identified as "the killer", and the lists patients were given of forbidden foods included most plant-derived nourishment. As soon as dialysis became more efficient and survival increased, hyperphosphatemia, was identified as the enemy, generating an even longer list of banned aliments. Conversely, the "third era" finds us combating protein-energy wasting. This review discusses four questions and four paradoxes, regarding the diet-dialysis dyad: are the "magic numbers" of nutritional requirements (calories: 30-35 kcal/kg; proteins > 1.2 g/kg) still valid? Are the guidelines based on the metabolic needs of patients on "conventional" thrice-weekly bicarbonate dialysis applicable to different dialysis schedules, including daily dialysis or haemodiafiltration? The quantity of phosphate and potassium contained in processed and preserved foods may be significantly different from those in untreated foods: what are we eating? Is malnutrition one condition or a combination of conditions? The paradoxes: obesity is associated with higher survival in dialysis, losing weight is associated with mortality, but high BMI is a contraindication for kidney transplantation; it is difficult to limit phosphate intake when a patient is on a high-protein diet, such as the ones usually prescribed on dialysis; low serum albumin is associated with low dialysis efficiency and reduced survival, but on haemodiafiltration, high efficiency is coupled with albumin losses; banning plant derived food may limit consumption of "vascular healthy" food in a vulnerable population. Tailored approaches and agreed practices are needed so that we can identify attainable goals and pursue them in our fragile haemodialysis populations.

Effect of Mealtime During Hemodialysis on Patients' Complications

Introduction: Food intake during hemodialysis increases the risk of problems such as hypotension, nausea, and vomiting in patients undergoing hemodialysis. This study aimed to determine the effect of mealtime during dialysis on the patients' complications. Methods: This is a quasi-experimental study consisted of all eligible hemodialysis patients in Hamadan teaching hospitals. All of 48 patients were selected through census method. The research was conducted in two sessions. At both sessions, patients were kept fasting prior to hemodialysis. In the first session, after one hour and in the second session after two hours of hemodialysis, a meal containing 350 kcal of energy was given to the patients. Blood pressure and intensity of nausea and vomiting was measured and recorded immediately before the start of hemodialysis, and then every half an hour before the termination of the hemodialysis. Results: The results showed that in both sessions, food intake caused a drop in the systolic and diastolic blood pressure, but changes in the mealtime had no effect on the systolic and diastolic blood pressure. Also, statistical test showed that changes in the mealtime had no significant impact on the intensity of nausea and vomiting. Conclusion: Food intake during hemodialysis had no effect on the nausea and vomiting, but caused a drop in the systolic and diastolic blood pressure, the drop continued for one hour and one and a half hour after the meal. It is suggested, mealtime in the early hours of hemodialysis could be better managed during the hemodialysis process.

The effects of resistance exercise and oral nutritional supplementation during hemodialysis on indicators of nutritional status and quality of life

BACKGROUND

Protein-energy wasting (PEW) is common in patients undergoing hemodialysis (HD). Studies have assessed the positive effect of oral nutritional supplementation (ONS) or resistance exercise (RE) on nutritional status (NS) markers in patients undergoing HD.

METHODS

The aim of this study was to assess the effect of ONS and RE on NS and the quality of life (QOL) of 36 patients undergoing HD. In a randomized clinical trial, patients were divided into the following two groups: a control group (ONS) that received a can of ONS during their HD sessions and an intervention group (ONS + RE) that received a can of ONS and underwent a 40-min session of RE during their HD sessions. Both interventions lasted 12 weeks. The patients' anthropometric, biochemical, dietetic and bioelectrical impedance measurements as well as their QOL, evaluated using the Kidney Disease Quality of Life Short Form, were recorded.

RESULTS

At baseline, 55.5% of patients presented with PEW according to International Society of Renal Nutrition and Metabolism criteria (20 patients). We found statistically significant changes from baseline in both groups, such as increases in body weight, body mass index, midarm circumference, midarm muscle circumference, triceps skinfold thickness, fat mass percentage, handgrip strength, phase angle and serum albumin. A decrease in the prevalence of PEW was observed in both groups at the end of the intervention. A delta comparison between groups showed no statistically significant differences in the anthropometric and biochemical parameters. No significant improvement was observed in QOL and body composition measured by bioimpedance vector analysis. Dietary energy and protein intake increased significantly during the study period for all patients.

CONCLUSION

Oral nutritional supplementation during HD improves NS. The addition of RE during HD does not seem to augment the acute anabolic effects of intradialytic ONS on NS.

Nutrition, vitamin D, and health outcomes in hemodialysis: time for a feeding frenzy?

PURPOSE OF REVIEW

The role of nutrition and nutritional supplementation in dialysis recently has been reinvigorated, with small clinical trials exploring surrogate outcomes and larger epidemiologic studies generating treatment hypotheses requiring further study. The present review focuses on major aspects of nutrition and outcomes in hemodialysis patients: protein and calorie intake and nutritional vitamin D supplementation.

RECENT FINDINGS

Building on data from small studies, two large, quasi-experimental cohort studies showed significant mortality benefits associated with oral nutritional supplements provided during dialysis, suggesting potential options for ameliorating the protein-energy wasting that is common in dialysis patients and associated with poor outcomes. Multiple cohort studies suggest, both in the general population and in dialysis, that higher 25(OH) vitamin D levels are associated with improved outcomes; however, no major mortality trials exist in dialysis, and the smaller, surrogate studies conducted to date have been disappointing, showing no consistent benefits in surrogate outcomes including inflammation and anemia, despite appropriate responses of vitamin D levels to repletion.

SUMMARY

Nutritional interventions are attractive options for improving outcomes in dialysis patients. Nutritional protein supplements have considerable promise, but require further study, preferably in a large, generalizable pragmatic trial. Small nutritional vitamin D supplementation trials in dialysis have had disappointing results. In the absence of new data, there appears to be no role for routine assessment or repletion of 25(OH) vitamin D deficiency or insufficiency in dialysis.

Preservation of residual kidney function in hemodialysis patients: reviving an old concept

Residual kidney function (RKF) may confer a variety of benefits to patients on maintenance dialysis. RKF provides continuous clearance of middle molecules and protein-bound solutes. Whereas the definition of RKF varies across studies, interdialytic urine volume may emerge as a pragmatic alternative to more cumbersome calculations. RKF preservation is associated with better patient outcomes including survival and quality of life and is a clinical parameter and research focus in peritoneal dialysis. We propose the following practical considerations to preserve RKF, especially in newly transitioned (incident) hemodialysis patients: (1) periodic monitoring of RKF in hemodialysis patients through urine volume and including residual urea clearance with dialysis adequacy and outcome markers such as anemia, fluid gains, minerals and electrolytes, nutritional, status and quality of life; (2) avoidance of nephrotoxic agents such as radiocontrast dye, nonsteroidal anti-inflammatory drugs, and aminoglycosides; (3) more rigorous hypertension control and minimizing intradialytic hypotensive episodes; (4) individualizing the initial dialysis prescription with consideration of an incremental/infrequent approach to hemodialysis initiation (e.g., twice weekly) or peritoneal dialysis; and (5) considering a lower protein diet, especially on nondialysis days. Because RKF appears to be associated with better patient outcomes, it requires more clinical and research focus in the care of hemodialysis and peritoneal dialysis patients.

In-Center Nutrition Practices of Clinics within a Large Hemodialysis Provider in the United States

BACKGROUND AND OBJECTIVES

Eating during hemodialysis treatment remains a controversial topic. It is perceived that more restrictive practices in the United States contribute to poorer nutritional status and elevated mortality compared with some other parts of the world. However, in-center food practices in the United States have not been previously described.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In 2011, we conducted a survey of clinic practices and clinician (dietitian, facility administrator, and medical director) opinions related to in-center food consumption within a large dialysis organization. After the initial survey, we provided clinicians with educational materials about eating during treatment. In 2014, we performed a follow-up survey. Differences in practices and opinions were analyzed using chi-squared tests and logistic regression.

RESULTS

In 2011, 343 of 1199 clinics (28.6%) did not allow eating during treatment, 222 clinics (18.2%) did not allow drinking during treatment, and 19 clinics (1.6%) did not allow eating at the facility before or after treatment. In 2014, the proportion of clinics that did not allow eating during treatment had declined to 22.6% (321 of 1422 clinics), a significant shift in practice (P<0.001). Among the 178 (6.8%) clinics that self-reported that eating was "more allowed" in 2014, the main reason for this shift was an increased focus on nutritional status. Among clinicians, a higher percentage encouraged eating during treatment (53.1% versus 37.4%; P<0.05), and facility administrators and medical directors were less concerned about the seven reasons commonly cited for restricting eating during treatment in 2014 compared with 2011 (P<0.05 for all).

CONCLUSIONS

We found that 28.6% and 22.6% of hemodialysis clinics within the United States restricted eating during treatment in 2011 and 2014, respectively, a rate more than double that found in an international cohort on which we previously published. However, practices and clinician opinions are shifting toward allowing patients to eat. Additional research is warranted to understand the effect that these practices have on patient outcomes and outline best practices.